There are generally disclosed developer compositions, and more specifically, developer compositions containing carriers. In embodiments, the carrier particles can be comprised of a core, a polymer, or mixture of polymer coatings thereover, and which coating or coatings have incorporated therein a conductive component, such as a conductive carbon black, and an alkali metal sulfate, such as a sodium lauryl sulfate, and wherein the resulting carriers are conductive, for example a carrier conductivity of from about 10−6 to about 10−12 ohm-cm−1. The carriers may be mixed with a toner of resin, colorant, and optional toner additives to provide developers that can be selected for the development of images in electrostatographic, especially xerographic imaging systems, printing processes and digital systems, including color processes.
Advantages of the carriers in embodiments illustrated herein include, for example, enabling carriers with high conductivities, such as from about 10−4 to about 10−15, and more specifically, from about 10−6 to about 10−8; tunable triboelectric charges, that is where such charges can be preselected; low economical coating weights, such as for example, from about 0.005 percent to about 1 percent, and more specifically, from about 0.05 to about 0.5 percent, and which weights permit excellent carrier surface coverage; low conductive component amounts, such as from about 0 to about 20, and more specifically, from about 1 to about 10; maintaining the carrier triboelectric charge at from about 18 to about 25 microcoulombs per gram and a conductivity of from about 10−8 to about 10−6 (1 ohm-cm) at, for example, a 10 volt potential across a 0.1 inch gap containing carrier beads held in place by a magnet; and wherein the carrier particles are of a triboelectric charging value of from about 15 to about 65 microcoulombs per gram, and more specifically, from about 15 to about 25 microcoulombs per gram as determined by a Faraday Cage, these parameters being dependent, for example, on the carrier coatings selected, and the percentage of each of the polymers present, and the conductive polymer; and wherein the carriers can be mixed with toners, including magnetic or MICR toners.